Tray wrapping apparatus and method

ABSTRACT

The invention is a novel and improved apparatus and process for applying a flexible cover such as aluminum foil to a tray such as a frozen dinner tray. The apparatus includes a conveyor belt for moving the tray, applicator means for cutting aluminum foil and placing it atop the tray, means adjacent the sides of the belt for folding the aluminum foil downwardly, means adjacent the sides of the belt for tucking the aluminum foil beneath the side lips of the tray and means which extend across the width of the belt for tucking the aluminum foil beneath the leading and trailing lips of the tray. In a preferred embodiment the apparatus also includes means for creasing the aluminum foil near the leading corners of the tray and means for creasing the aluminum foil near the trailing corners of the tray to provide a better fit of the foil about the corners and to aid in the folding and tucking of the foil about the flange surrounding the tray.

United States Patent [191 Davis [451 Feb. 18,1975

[ TRAY WRAPPING APPARATUS AND- METHOD [75] Inventor: Raymond A. Davis, Belmont, Calif.

[73] Assignee: Frank A. Grant, Burlingame, Calif.

[22] Filed: July 5, 1973 [21] Appl. No.: 376,336

[52] U.S. Cl 53/42, 53/329, 53/333 [51] Int. Cl B65b 7/28 [58] Field of Search. 53/42, 329, 333, 287, 282, 53/41, 184, 45, 46, 300, 306, 371, 297, 334,

Primary Examiner-Travis S. McGehee Assistant Examiner-Horace M. Culver Attorney, Agent, or FirmPhillips, Moore, Weissenberger, Lempio & Strabala [57] ABSTRACT The invention is a novel and improved apparatus and process for applying a flexible cover such as aluminum foil to a tray such as a frozen dinner tray. The apparatus includes a conveyor belt for moving the tray, applicator means for cutting aluminum foil and placing it atop the tray, means adjacent the sides of the belt for folding the aluminum foil downwardly, means adjacent the sides of the belt for tucking the aluminum foil beneath the side lips of the tray and means which extend across the width of the belt for tucking the aluminum foil beneath the leading and trailing lips of the tray. In a preferred embodiment the apparatus also ineludes means for creasing the aluminum foil near the leading corners of the tray and means for creasing the aluminum foil near the trailing corners of the tray to provide a better fit of the foil about the corners and to aid in the folding and tucking of the foil about the flange surrounding the tray.

25 Claims, 30 Drawing Figures PATENTEDFEBI Big-7s 3,866,387

SHEET 1 [IF 9 PATENTED 3,866,387

SHEET 7 OF 9 52 FIG 22 PATENTED 81975 3.866 387 saw 8 0F 9 87FIG..26

TRAY WRAPPING APPARATUS AND METHOD BACKGROUND OF THE INVENTION The invention relates to an apparatus for wrapping a sheet of a material such as aluminum foil atop a tray such as a frozen dinner tray and a process for wrapping a sheet of material about a tray.

The prior art discloses a number of packaging machines which serve to wrap dinner trays with aluminum foil or the like so that the trays are put in condition for fast freezing and later sale. The apparatus of the prior art has generally been quite complex especially with respect to the means utilized for folding the foil under the leading and trailing lips of the tray. Illustrative prior art packaging machines are disclosed in part or in whole in US. Pat. Nos. 2,926,473; 2,928,222; 2,950,590; 2,975,574; 2,982,073; 3,116,580; 3,253,380; 3,263,393 and 3,371,465.

The packaging machine of US. Pat. No. 2,928,222

for example, requires that the tray being wrapped as it advances along a belt be rotated 90 after the sheet has been folded and tucked under the sides of the tray so that the originally leading and trailing edges become side edges prior to the folding and tucking of the sheet under them. I Further, the prior art apparatus is not easily adaptable to wrapping the trays from duplex filling lines now commonly in use nor to handling a number of trays simultaneously in a relatively small working area through providing as many as two parallel belts and wrapping stations.

As a result of the increasing proportion of foods which are prepackaged in trays, it is becoming increasingly necessary to provide fast, efficient and reliable tray-wrapping equipment. Further, it is desirable to provide tray-wrapping equipment which will provide uniformly wrapped trays wherein the aluminum foil or the like is tightly taut beneath the tray flanges. This is desirable because foil wrapped trays are often packaged in cartons after freezing and any loose foil can interfere with the packaging.

Accordingly, it is an object of the present invention to provide a tray-wrapping apparatus which takes up less space, per tray wrapped, because it can wrap trays from a duplex filling line, thus avoiding the use of two separate wrapping machines.

It is another object of the invention to provide a traywrapping apparatus which will more uniformly apply aluminum foil about the flange of a tray.

Yet another object of the invention is to provide a tray-wrapping apparatus which will uniformly apply aluminum foil or the like about the flange of the tray and which does not require that the tray be rotated as part of the aluminum foil application procedure.

Still another object of the present invention is to provide a tray-wrapping apparatus which includes means for creasing the corners of aluminum foil being applied to the tray whereby the folding and tucking operations at the sides, front and back of the tray provide a more uniform wrapping of the aluminum foil about the tray.

A preferred form of the wrapping apparatus of the present invention is disclosed in the accompanying drawings which are incorporated herein by reference thereto and in which like numbers denote like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a typical frozen dinner tray.

FIG. 2 illustrates in an overall perspective view a preferred tray-wrapping apparatus of the present invention utilizing two conveyor belts and two wrapping stations.

FIG. 3 illustrates in a side elevation view the apparatus of FIG. 1.

FIG. 4 illustrates in a plan view a preferred apparatus of the present invention utilizing a single conveyor belt.

FIG. 5 illustrates in a side view the conveyor belt and attendant tray-positioning and foil-tucking arms of the preferred embodiment of the invention.

FIG. 6 is a plan view illustrating the same mechanisms as FIG. 5.

FIG. 7 is a section view of FIG. 5 and further illustrates the conveyor belt of the preferred embodiment of the present invention.

FIG. 8 is a plan view illustrating details in the preferred primary side folding, primary corner creasing, and primary front and rear folding portions of the apparatus.

I FIG. 9 is a section view of FIG. 8.

FIG. 10 is a plan view illustrating details in the preferred secondary side folding, secondary corner creasing and secondary front and rear folding portions of the apparatus.

FIG. 11 is a section view of FIG. 10.

FIG. 12 is a front elevation illustrating the detail of FIG. 8 with a tray in place.

FIG. 13 is a section of FIG. 12.

FIG. 14 is a side elevation illustrating the preferred primary front folding and primary corner creasing portions of the present invention in operation.

FIG. 15 is a front view of the portions of the apparatus shown in FIG. 14.

FIG. 16 is a plan view of the portions of the apparatus shown in FIG. 14.

FIG. 17 is a plan view illustrating the preferred side tucking means of the present invention.

FIG. 18 is a side view illustrating the side tucking means shown in FIG. 17.

FIG. 19 is a side elevation illustrating preferred secondary corner creasing and secondary front folding portions.

FIG. 20 is a partial front view of FIG. 19.

FIG. 21 is a plan view of the apparatus shown in FIG.

FIG. 22 is a side elevation illustrating the preferred primary rear folding and primary trailing corner creasing portions of the apparatus as used adjacent the rear of the tray.

FIG. 23 is a plan view of the apparatus shown in FIG. 22.

FIG. 24 is a front view of the apparatus shown in FIG. 22.

FIG. 25 illustrates a section of the cam track utilized in the preferred embodiment of the invention.

FIG. 26 is aside elevation view illustrating details of the smoothing means, the preferred secondary rear folding means and secondary trailing corner creasing means and further illustrating the preferred front and rear tucking means.

FIG. 27 is a side elevation view illustrating the preferred mode of tucking under the trailing lip and the preferred mode of final smoothing of the aluminum foil against the trailing lip of the tray.

FIG. 28 is a front view of the apparatus shown in FIG.

FIG. 29 illustrates details in the side folding and side tucking of the preferred apparatus of the invention.

FIG. 30 illustrates the tray flange carrying belts and the side tucking means of the preferred embodiment in some detail.

GENERAL DESCRIPTION OF THE INVENTION In the broad sense, the invention is an apparatus and process for applying a flexible cover to a tray having a peripheral flange.

The apparatus comprises a conveyor belt for moving a tray along a predetermined path, with two opposite sides of the tray parallel to the direction of movement; applicator means adjacent the path of movement of the tray for placing a flexible cover sheet on the tray; primary side folding means adjacent the sides of the belt for downwardly folding the sheet about the side lips of the flange; tucking means adjacent the side of the belt for tucking the sheet beneath the side lips of the flange; and front and rear tucking means adjacent and across the width of the belt for tucking the sheet beneath the flange adjacent the leading lip and the trailing lip, respectively, of the flange.

In a preferred embodiment of the invention, the apparatus further includes, adjacent the primary side folding means, first leading corner creasing means adjacent the sides of the belt for downwardly creasing the sheet adjacent the leading corners of the flange and first front folding means across the width of the belt for folding downwardly the leading margin of said sheet adjacent the leading lip.

In a more preferred embodiment, the apparatus further includes, adjacent the side folding means, first trailing corner creasing means adjacent the sides of the belt for downwardly creasing the sheet adjacent the trailing corners of the flange, and first rear folding means across the width of the belt for folding downwardly the trailing margin of said sheet adjacent the trailing lip.

In a still more preferred embodiment of the invention, the apparatus also includes downstream of the side folding means a secondary side folding means adjacent the sides of the belt for further downwardly folding the sheet about the side lips of the flange.

In a yet more preferred embodiment, the apparatus additionally includes a means for smoothing the sheet where it rests atop the side lips while pressing upwardly upon the tucked portion of the sheet below the side lips of the flange.

The process of the present invention is a process for applying a flexible cover to a continuously advancing tray having a peripheral flange defining a leading lip, a trailing lip, side lips, leading corners and side corners. The process comprises:

positioning a flexible cover sheet over the tray so that the margins of the sheet project beyond the flange of the tray; folding downwardly the side margins of the sheet adjacent the side lips of said flange; downwardly creasing the corners of the sheet adjacent the leading and trailing corners of the flange; tucking the side margins of said sheet below the side lips of said flange; tucking the leading margin of said sheet beneath the leading lip of said flange; and tucking the trailing margin of the sheet beneath the trailing lipof said flange whereby the tucked margins substantially conform to the contours of the flange.

In a preferred embodiment the process further comprises, prior to said tucking of the leading margin of said sheet beneath the leading lip of said flange, folding downwardly the margin of said sheet adjacent the leading lip of said flange, and prior to said tucking of the trailing margin of said sheet beneath the trailing lip of said flange, folding downwardly the margin of said sheet adjacent the trailing lip of said flange.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be still better understood by reference to the detailing description of the preferred embodimentsthereof which follows.

FIG. 1 illustrates a typical rigid rectangular tray 1 such as a frozen dinner tray. The tray has a peripheral flange 2. The leading lip of the flange is denoted by 3, the leading corners by 5, the trailing lip by 7, the trailing corners by 9, and the side lips by 11. It is understood that tray dimensions and shapes vary considerably and the invention is, of course, not meant to be limited to the size or shape of any particular tray.

FIG. 2 is an overall perspective view of the packaging machine 13 of the present invention. The packaging 1 machine 13 includes legs 15 which support a frame 17.

A relatively standard aluminum feeding and tensioning assembly is indicated generally at 19. This assembly 19 comprises a circular rod 21 for holding an aluminum foil roll 23. The registration sensor 24 and register control box 26 are conventional and are used to register the printed aluminum foil from the roll 23. Referring to FIGS. 2 and 3 primarily, aluminum foil guides 27 are illustrated along with aluminum length cutting members 28 and foil slitting member 30. The direction of the aluminum foil is indicated by arrowheads in FIG. 3.

The amount of aluminum cut by the feeding and tensioning assembly 19 is sufficient to completely cover the top of each of the trays l and to partially overlap the flange 2 at each of the lips 3, 7 and 11, as well as at the corners 5 and 9.

Referring once again primarily to FIG. 2, the chain conveyor belts 29 are shown. In FIG. 4 a single chain conveyor belt 29 is shown to illustrate that the packaging machine of the present invention can be made with a single conveyor belt or with two such belts. The conveyor belts 29 move from left to right in FIGS. 2-6. For convenience and without limiting the invention thereby, the lefthand portion of the conveyor belt is herein occasionally referred to as the upstream portion thereof and the righthand portion of the conveyor belt is occasionally referred to as the downstream portion thereof. The conveyor belt or belts 29 are driven at the same speed as the front and rear rubber (or synthetic) guide belts 31 and 32, respectively, which are motivated by the pulleys 33. The pulleys 33 and belts 29 are I set in motion by, for example, an electric 'motor with necessary chain and gearing, and the like none of which is illustrated because of its highly conventional nature.

The chain conveyor belt 29 is composed of a plurality of links 35, each of the links 35 sitting upon a sprocket receptor 36 as illustrated most clearly in FIGS. 5 and 6. Successive sprocket receptors 36 are rotatably linked together by link bridges 38. The receptors 36, as

illustrated in FIG. 7, are driven by sprocket drive wheel t 40. Also illustrated in FIGS. 5 and 6 are the bent rocker arms 37 which serve two functions, the first function being to position a tray as it enters along the belt 29 through use of the tray-positioning bridges 39 and the second function being to tuck aluminum foil beneath the leading and trailing lips of the tray 1 through use of the tucking bars 41. The movement of the bent rocker arms 37 is controlled by the cam track 43 illustrated most clearly in FIGS. 26 and 27. The bent rocker arms 37 have rollers 45 attached thereto which are guided by the cam track 43, as the belt 29 is driven forward along with the belts 31.

In practice, a tray 1 (or in the case of duplex operations two trays 1) is caught between a pair of opposing tray-positioning bridges 39 and is carried forward by the movement of chain belt 29. The side lips 11 of the tray I sit successively upon belts 32, guides 107 and belts 31. The aluminum feeding and metering assembly 19 cuts off and positions a sheet 46 of aluminum foil atop the tray 1. The tray 1 then passes below the cylindrical surfaces 51 of a pair of rotatable wheels 47, each of the pair of rotatable wheels 47 having a rotatable disc 49 concentric therewith and exterior thereto relative to the conveyor belt 29. The wheels 47 and the discs 49 rotate as a unit whereby the closest approaching points of the discs 47 to the conveyor belt 29 travel in the same direction and at the same speed as the belt 29. Preferably the discs 49 have bevelled portions 52 thereon to insure that the tray 1 passes between the discs 49. (See FIGS. 8, 9 and 12 for details.)

The tray 1 with a sheet of aluminum foil thereupon passes along the belt between the discs 49. The side margins 50 of the sheet 46 are contacted on each side of the flange 2 and in particular, just at the edge of the side lips 11 of the tray 1 by the discs 49 which fold the side margins 50 downwardly. The foil atop the side lips 11 contacts the cylindrical surfaces 51 of the wheels 47 as illustrated best in FIG. 12. Thus the discs 49 fold the side margins 50 downwardly while the wheels 47 smooth the sheet 46 atop the side lips 11.

In the preferred embodiment, the sheet 46 atop the tray 1 is contacted adjacent the leading corners 5 by the first pair of nubs 53 is shown in FIGS. 14-16 whereby the leading margin 54 of the sheet 46 is folded downwardly. The first pair of nubs 53 downwardly creases the aluminum foil adjacent the leading corners 5 of the tray 1 so that later folding and tucking operations will lead to a more uniform wrapping of the tray 1.

The side margins 50 of the sheet 46, after being folded downwardly about the tray 1 contact the shelf 55 shown in FIGS. 17, 18, 29 and 30 which serves to tuck the sheet 46 of aluminum foil under the side lips 11. The shelf 55 has a ramp 57 for gradually tucking the approaching aluminum foil under the side lips 11. Thus, the sheet 46 of aluminum foil is first creased at its side margins 50 by the nubs 53, then folded downwardly by the discs 49 and finally smoothed on the top and tucked underneath the side lips 11 by the wheels 47 and the shelf 55, respectively.

A second pair of nubs 59 identical to the first pair of nubs 53 is also illustrated in FIGS. 8, 9, l2 and 13. The nubs 59 as shown in FIGS. 22, 23 and 24 serve to crease the trailing margin 60 of the sheet 46 of aluminum foil downwardly adjacent the trailing corners 9 and lip 7 of the tray 1. To accomplish this, the separation between the first pair of nubs 53 and the second pair of nubs 59 adjacent the circumference of the wheels 47 is substantially equal to but slightly greater in length than the length of the tray 1 from the forward edge of the leading lip 3 thereof to the trailing edge of the trailing lip 7 thereof.

In the preferred embodiment of the invention, the tray 1, after it leaves the first pair of wheels 47 and the first pair of discs 49, proceeds to contact a second side folding means 61 which preferably comprises a second pair of wheels 63 having a second pair of discs 65 positioned therewithout and concentric therewith, said second pair of wheels 63 and said second pair of discs 65 being positioned adjacent the sides of the belt 29. The second pair of discs 65 preferably have a bevelled portion 66 thereof which first contacts the side margins of the sheet 46 to insure containment of the tram 1. The shelf passes sufficiently below the cylindrical surface 67 of the second wheels 63 so that no contact of the side margins 50 occurs therewith beneath the cylindrical surface 67. The shelf 55 is upraised to its former height beyond the point of contact of the cylindrical surface 67 with the tray 1 to further tuck the side margins 50 of the sheet 46 under the side lips 11. Thus, the side margins 50 of the aluminum foil which has been folded downwardly and then tucked about the side lips I 1 by the first pair of wheels 47 in conjunction with the first pair of discs 49, the nubs 43 and the shelf 55, is again folded downwardly and again tucked beneath the side margins 50 of the sheet 46 by the second pair of wheels 63 and the extension of the shelf 55.

Also, second leading corner creasing means 69 are provided attached to said second pair of discs, said second leading corner creasing means 69 contacting the margins of the aluminum foil previously creased adjacent said leading corners 5 by said first pair of nubs 53. A pair of second trailing corner creasing means 71 are also provided attached to the said second pair of discs for contacting the foil previously creased adjacent to said trailing corners 9.

The second side folding means 61, comprising the second pair of wheels 63 and the second pair of discs 66 is timed to rotate at such a speed that the point on the surface of said second pair of wheels which passes closest to said belt 29 moves in the same direction thereas and moves at the same speed as said belt 29. The separation of said pair of second leading corner creasing means 69 from said pair of second trailing corner creasing means 71 adjacent the circumference of second pair of discs 65, is adjusted to be substantially equal to but slightly longer than the length of said tray 1, from the leading edge of leading lip 3 to the trailing edge of the trailing lip 7.

As is apparent from FIGS. 26-30, after the leading lip 3 of said tray 1 leaves said second side folding means 61, the tray 1 passes under a pair of rubber smoothing cylinders 73. Center pulley 74 of downstream belts 31 is beneath the pair of rubber smoothing cylinders 73 and thus provides support for the smoothing action of the cylindrical surfaces 75 of the rubber smoothing cylinders 73.

As the tray 1 passes under the rubber smoothing cylinders 73, the bent rocker arms 37 rock back and contact and tuck under the leading and trailing margins of the aluminum foil about the leading lip 3 and the trailing lip 7, respectively, of tray 1. The bars 41 extending between opposing of the bent rocker arms 37 perform this operation as a result of the movement of the rollers 45 within the cam track 43. The bars 41 have contacting ramps 42 which mate with the sides of the tray 1 beneath the leading lip 3 and the trailing lip 7. FIGS. 26 and 27 illustrate the actions of the downstream and the upstream rollers 45.

It will be noted by reference to the drawings that the first pair of wheels 47 and the first pair of discs 49 are generally made of a single piece of bar stock and that said pairs are further generally connected together for proper coordination via axle 77. Similarly the second pair of wheels 63 and the second pair of discs 75 are generally made of a single piece of bar stock and are generally connected together for proper coordination via the axle 79. The rubber smoothing cylinders 73 are also generally connected together for proper coordination via smoothing cylinder axle 81. The axle 77 desirably connects to the wheels 47 via a shoulder 83; the axle 79 generally connects to the wheel 63 via the shoulder 85; the smoothing cylinders axle 81 generally connects to the smoothing cylinders 73 via the shoulder The construction of the first pair of nubs 53 used in the preferred embodiment of the invention is shown in greatest detail in FIGS. 8, 9, l2 and 13. Generally the nubs 53 are mounted to the discs 49 exterior radially of the cylindrical surface 51 of the pair of wheels 47 and the interior of said discs 49 relative to said belt 29. The second pair of nubs'59 are mounted, in a preferred embodiment of the invention, to the interior (relative to the belt 29) surface of the discs 49, exterior radially of the cylindrical surface 51 of the wheels 47. In the preferred embodiment, a rod 89 runs from one of the pair of nubs 53 to the other and a rod 91 runs from one of the pair of nubs 59 to the other. The use of the common axle 77 for the discs 49 and the rods 89 and 91 for the first pair of nubs 53 and the second pair of nubs 59, respectively, insures the coordinated action'of all parts of the first packaging assembly 93. It will be noted that the first pair of nubs 53 and the second pair of nubs 59 each extend slightly beyond the .diameter of the discs 48 whereby the nubs readily contact and crease aluminum foil or the like downwardly adjacent to the corners of the flange 2 of the tray 1.

The creasing of the aluminum foil by the first pair of nubs 53 and the ramps 95 about the leading corners of the tray 1 has generally slightly folded downwardly the aluminumfoil about the leading lip 3 so that the tucking bar 41 catches the aluminum foil from the top. The second pair of nubs 59 and the ramps 97 act similarly with respect to the foil about the trailing lip 7. FIG. 27 illustrates the action of the cam track 43 upon the bent rocker arm 37 at the upstream end of the tray 1. Again, movement of the bent rocker arm 37 about the pivot 99 thereof leads to the tucking bar 41 being guided to beneath the trailing lip 7 of the flange 2 of the tray 1 and to the tucking of aluminum foil beneath the trailing lip 7.

Further, the rods 89 and 91 serve the important pur pose of more positively folding downwardly the margins of the sheet 46 adjacent the leading lip 3 and the trailing lip 7, respectively, of the tray 1. The downward fold imparted to the leading and trailing margins of the sheet 46 adjacent to the leading lip 3 and the trailing lip 7 contributes to the efficiency of tucking attainable by the cam driven action of the tucking bars 41.

Referring now particularly to FIGS. and 11, the details in the construction of the second side folding means 61 will be most apparent. The connecting together of the discs via the axle 79 has been previously discussed. The second leading corner creasing means 69, in the preferred embodiment of the invention, comprises a generally rectangular shaped bar 94 spanning the distance between the second pair of discs 65 and being located generally external radially of the cylindrical surface 67 of the second pair of wheels 63 and internally relative to the belt 29 to the second set of discs 65. The second leading corner creasing means 69 in a preferred embodiment of the invention deviates from being completely rectangular in that adjacent the discs 65 the second leading corner creasing means 69 is provided with ramps 95 which are adapted to mate closely with the aluminum foil adjacent the leading corner 5 of the flange 2 of the tray 1, thereby creasing the aluminum foil about said leading corners 5. Similarly, the second trailing corner creasing means 71 is generally rectangular shaped bar 96 and spans the distance between the discs 65. The bar 96 also deviates from the rectangular in that it has a pair of ramps 97 which are adapted to closely mate about the trailing corners 9 of the flange 2 of the tray 1.

Further, the bars 94 and 96 serve the purpose of once again folding downwardly the margins of the sheet 46 adjacent the leading lip 3 and the trailing lip 7, respectively, of the tray 1. The downwardly folding of the leading and trailing margins of the sheet 46 further contributes to the efficiency of tucking by the cam driven action of the tucking bars 41.

The bent rocker arms 37 have been previously briefly discussed with reference to FIGS. 5 and 6. The full operation of the bent rocker arms 37 in conjunction with the cams 43 will be better understood by reference to FIGS. 26 and 27. As is apparent from FIGS. 5 and 6 and as was previously mentioned, the bent rocker arms 37 include tray positioning bars 39 which serve to hold a tray 1 between a pair of facing tray-positioning bars 39 while the tray is traveling throughout the machine. In operation, the traypositioning bars 39 are held in place between successive links 35 of chain belt 29 so that the tray positioning bars 39 are immovable. The bent rocker arms 37 are pivoted to the tray positioning bars 39 at the pivot 99 and further pivotally mounted to the rollers 45 via the short axle 101.

When the rollers 45 advance along the cam track 43, a vertical motion of the rollers 45 is thus initiated along with a swinging (arcuate) motion of the bent rocker arms 39 about the pivot 99. Referring most particularly to FIGS. 26 and 27, the result of the guiding of the rollers 45 along the cam track 43, namely the forcing of the tucking bars 41 up under the and substantially parallel to flange 2 of the tray 1 adjacent the leading lip 3 and the trailing lip 7, respectively, is apparent.

Referring in particular to the bent rocker arm 37 on the righthand side of FIG. 26, it is apparent that the roller 45 when it enters the lower portion of the cam track 43, leads to a rotation of the righthand bent rocker arm 37 about the pivot 99 to contact the tucking bar 41 of said righthand bent rocker arm 37 with the tray 1 below the leading lip 3 thereof. Thus, any aluminum foil or the like previously bent downwardly about leading lip 3 is tucked beneath the leading lip 3.

It will be further noted from reference to FIGS. 26 and 27 that in the preferred embodiment of the invention the tucking bars 41 are used to tuck aluminum foil beneath the. leading lip 3 and the trailing lip 7 of the flange 2, while the tray 1 is positioned between the cylindrical surface of rubber smoothing cylinders 73 and the top surface of the downwstream belt 31 of center pulley 74 whereby the tucking action by the tucking bars 41 can be positively and securely accomplished.

Reference to FIGS. 29 and 30 will make clearer some details of the side tucking and smoothing portions of the preferred embodiments of the invention. FIG. 30 shows the pulleys 33. The leftmost pulley 33 in conjunction with the large pulley 103 causes the belts 32 to rotate in a clockwise direction. Similarly, the belt 31 is rotated in a clockwise direction by the large pulley 74 and the rightmost pulley 33. A tray being propelled along the chain belt 29 has its side lips 11 first upon a belt 32, then upon support rail 107, and then upon belt 31. Shelf 55 and ramp 57 are usually parts of rail 107 which is generally made of nylon or a similar material. FIG. 30 illustrates the operation of rail 107 and belt 31 in conjunction with primary packaging assembly 93, secondary packaging assembly 61, and smoothing cylinder 73. The tray hold down wheels 109 and 111 serve to keep the fronts of trays from flipping upwardly under the impetus of rotating assemblies 93 and 61, as the trays leave said assemblies. Each of the wheels 109 and 11 sits upon a side lip 11 of a tray 1 as the tray passes downstream under the impetus of the belt 29.

The process of the present invention can also be easily followed and better understood by reference to the drawings herein although, of course, the process is not limited to use of the particular apparatus shown in these drawings.

In the preferred embodiment of the invention as will be seen, for example, in FIG. 12, a sheet 46 of flexible material such as aluminum foil, which is atop the tray 1, is contacted adjacent the side lips 11 by the discs 49 and thereby folded downwardly. The corners of aluminum foil adjacent the leading corners of the tray 1 are creased downwardly through contact with the first pair of nubs 53 as may be seen in FIG. 14. As the tray 1 proceeds forwardly under the impetus of the belt 29 the downwardly folded margins of the aluminum foil adjacent the side lips 11 of the flange 2 of the tray 1 are tucked beneath the side lipsll by the action of the shelf 55 shown in FIGS. 17 and 18. As the trailing lip of the tray 1 departs from the primary packaging assembly 93 the corners of the aluminum foil adjacent the trailing corners 9 are creased downwardly through action of the second pair of nubs 59 as shown in FIG. 22.

In a preferred embodiment, the leading and trailing margins 54 and 60, respectively, of the sheet 46 are downwardly folded adjacent the leading lip 3 and the trailing lip 7, respectively, of the tray 1 before said leading margin 54 and said trailing margin 60 are tucked beneath said leading lip 3 and trailing lip 7, re spectively. The downward folding places the margins in better position for smooth and effective tucking by the tucking bars 41.

-In a preferred embodiment of the invention as shown for example, in FIG. 26, the margins of the aluminum foil adjacent the side lips 11 are refolded downwardly by the second pair of discs 65.

In a further preferredembodiment, the margins of the aluminum foil adjacent the leading corners 5 and the trailing corners 9 are recreased through contact of the margins of the aluminum foil adjacent the leading corners 5 and the trailing corners 9, respectively, with the second leading corner creasing means 69 and the second trailing corner creasing means 71.

In another preferred embodiment illustrated in FIGS. 26 and 27, the margins of the aluminum foil atop the side lips 11 of the flange 2 are smoothed through contact therewith with the rubber smoothing cylinders 73.

As is further shown in FIGS. 26 and 27, the leading margin of the aluminum foil is tucked beneath the leading lip 3 of the flange 2 of the tray 1 by the action of the leading bent rocker arms 37 whereby the tucking bar 41 does the actual tucking. As may be seen from FIG. 27, the tucking of the margin of the aluminum foil adjacent the trailing lip 7 of the flange 2 of the tray 1 is similarly accomplished through action of the trailing rocker arm of the bent rocker arms 37 utilizing the tucking bar 41 thereof.

While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of furhter modification, and this application is intended to cover any variations, uses or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as fall within the scope of the invention and the limits of the appended claims.

I claim:

1. A process for applying a flexible cover to a continuously advancing open tray having a peripheral flange defining a leading lip, a trailing lip, side lips, leading corners and side corners, comprising:

a. positioning a sheet of flexible material over the advancing tray so that the margins of the sheet project beyond the flange of the tray;

b. folding downwardly at a folding station in one continuous motion the side margins, the leading margin and the trailing margin of the sheet adjacent the side lips, leading lip and trailing lip, respectively, of said flange;

c. tucking the side margins of the sheet below the side lips of said flange; then (1. tucking the leading margin of the sheet beneath the leading lip of said flange; and thereafter e. tucking the trailing margin of the sheet beneath the trailing lip of said flange so that the tucked margins conform to the contour of the flange.

2. A process as in claim 1 including during and as a part of said folding step (b), creasing downwardly the corners of said sheet adjacent the leading corners of said flange.

3. A process as in claim 2 including during and as a part of said folding step (b), creasing downwardly the corners of said sheet adjacent the trailing corners of said flange following said creasing downwardly of the margins of said sheet adjacent the leading corners of said flange.

4. A process as in claim 3 including as an added step after said first tucking step (c), refolding downwardly at a refolding station in one continuous motion the side margins, the leading margin and the trailing margin of said sheet about the side lips, leading lip and trailing lip,

respectively, of said flange.

5. An apparatus for applying a flexible cover to a tray having a peripheral flange, comprising:

1 l l. a conveyor belt for moving a tray along a predetermined path with two opposite sides of the tray parallel to the direction of movement thereof; 2. applicator means adjacent the path of movement of the tray for placing a flexible cover sheet on the tray; 3. a folding station at which said sheet is positioned down around the periphery of said flange in a single continuous movement, comprising: 4 a. a pair of rotatable wheels adjacent the sides of said belt and on. opposite sides thereof, said wheels being positioned so that their cylindrical surfaces hold the top of said sheet against the tops of the side lips of said flange at the point of contact of said cylindrical surfaces with said sheet;

b. a pair of rotatable discs exterior of said wheels relative to said belt and having a common axle with said wheels, said discs and said wheels being constrained to rotate as a unit, said discs having a' larger diameter than said wheels, s-aid discs serving to downwardly fold said sheet adjacent Y the side lips of said flange;

c. leading lip folding means extending from one to the other of said discs and parallel to the common axle thereof near the circumferences thereof and d. trailing lip folding means extending from one to the other of said discs and parallel to the common axle thereof near the circumferences thereof, said trailing lip folding means being spaced from said leading lip trailing means adjacent the circumferences of said discs by a separation slightly greater than the dimension of said tray including said flange along the direction of movement of said belt;

4. side tucking means adjacent the sides of said belt for tucking said sheet beneath the side lips of said flange; and

5. front and rear tucking means downstream of said folding station adjacent and extending across the width of said belt for tucking said sheet beneath said flange adjacent the leading lip and the trailing lip, respectively, of said flange.

6. An apparatus as in claim 5 wherein said folding station includes leading corner creasing means communicating with said leading lip folding means and adjacent to said rotatable discs for downwardly creasing the corners of said sheet adjacent the leading corners of said flange.

7. An apparatus as in claim 6 wherein said folding station includes trailing corner creasing means communicating with said trailing lip folding means and adjacent said rotatable discs for downwardly creasing the corners of said sheet adjacent the trailing corners of said flange.

8. An apparatus as in claim 7 wherein said leading corner creasing means comprises a first pair of nubs attached near the circumferences of said discs in opposition to one another.

9. An apparatus as in claim 8 wherein said trailing corner creasing means comprises a second pair of nubs attached near the circumferences of said discs in opposition to one another.

10. An apparatus as in claim 5, including downstream of said folding station:

1. a refolding station at which said sheet is repositioned down around the periphery of said flange in a single continuous movement, comprising:

a. a second pair of rotatable wheels adjacent the sides of said belt and on opposite sides thereof, said wheels being positioned so that their cylindrical surfaces hold the top of said sheet against the tops of the side lips of said flange at the point of contact of said cylindrical surfaces with said sheet;

b. a second pair of rotatable discs exterior of said wheels relative to said belt and having a common axle with said second pair of wheels, said second pair of discs and said second pair of wheels being constrained to rotate as a unit, said second pair of discs having a larger diameter than said second pair of wheels, said second pair of discs serving to downwardly refold said sheet adjacent the side lips of said flange;

c. secondary leading lip folding means extending from one to the other of said second pair of discs and parallel to a common axle thereof near the circumferences thereof and d. secondary trailing lip folding means extending from one to the other of said second pair of discs and parallel to the common axle thereof near the circumferences thereof, said secondary trailing lip folding means being spaced from said secondary leading lip folding means adjacent the circumferences of said second pair of discs by a separation slightly greater than the dimension of said tray including said flange along the direction of movement of said belt.

11. An apparatus as in claim 10, wherein said refolding station includes secondary leading corner creasing means communicating with said secondary leading lip folding means adjacent said second pair of discs for downwardly recreasing the corners of said sheet adjacent the leading corners of said flange.

12. An apparatus as in claim 11, wherein said refolding station includes secondary trailing corner creasing means communicating with said secondary trailing lip folding means adjacent said second pair of discs for downwardly recreasing the corners of said sheet adjacent the traiing corners of said flange.

13. A process as in claim 4, including during and as a part of said refolding step, recreasin g downwardly the corners of said sheet adjacent the leading corners of said flange.

14. A process as in claim 13 including during and as a part of said refolding step, recreasing downwardly the corners of said sheet about the trailing corners of said flange following said recreasing downwardly of the corners of said sheetadjacent the leading corners of said flange.

15. An apparatus as in claim 5, wherein said front and rear tucking means comprise:

a pair of U-shaped members, one of which is in front of said tray and the other in the rear thereof, the arms of said U-shaped members extending below the level of said belt, and the bridges of said U- shaped members being extendable across the width of said belt.

16. An apparatus as in claim 5, wherein said side tucking means comprises a pair of shelves adjacent the sides of said belt.

17. An apparatus as in claim 7, wherein said front and rear tucking means comprise:

a pair of U-shaped members, one of which is in front of said tray and the other inthe rear thereof, the arms of said U-shaped members extending below the level of said belt, and the bridges of said U- shaped members being extendable across the width of said belt.

18. An apparatus as in claim 9, including:

means for positioning said tray on said belt whereby said first pair of nubs contact said sheet on said tray adjacent the leading corners of said flange; and

means for rotating said discs in concert whereby the closest approaching point of said wheels to said belt travels in the same direction and at the same speed as said belt.

19. An apparatus as in claim 18, wherein said front and rear tucking means comprise:

a pair of U-shaped members, one of which is in front of said tray and the other in the rear thereof, the arms of said U-shaped members extending below the level of said belt, and the bridges of said U- shaped members being extendable across the width of said belt.

20. An apparatus as in claim 12, including downstream of said refolding station:

means for smoothing said sheet atop said side lips of said flange.

21. A process as in claim 14 including as an added step after said first tucking step (c) smoothing the margins of said sheet atop said side lips.

22. An apparatus for applying a flexible cover to a tray having a peripheral flange which comprises:

1. a conveyor belt for moving a tray along a predetermined path with two opposite sides of the tray parallel to the direction of movement;

2. applicator means adjacent the path of movement of the tray for placing a flexible cover sheet on the tray;

3. side folding means adjacent the sides of said belt for downwardly folding said sheet adjacent the side lips of said flange, comprising:

a. a pair of rotatable wheels, said wheels being on opposite sides of said belt, said wheels being positioned so that their cylindrical surfaces hold the top of said sheet against the tops of the side lips of said flange at the point of contact of said cylindrical surfaces with said sheet; and

b. a pair of rotatable discs, said discs being exterior of said wheels relative to said belt and concentric with said wheels whereby said discs and said wheels rotate as a unit, said discs having a larger diameter than said wheels.

4. side tucking means adjacent the sides of said belt for tucking said sheet beneath the side lips of said flange;

5. front and rear tucking means adjacent and across the width of said belt for tucking said sheet beneath said flange adjacent the leading lip and the trailing lip, respectively, of said flange;

6. a first pair of nubs, the nubs of said first pair of nubs being attached near the circumferences of said discs in opposition to one another for downwardly creasing the corners of said sheet adjacent the leading corners of said flange.

7. 'means extending from one to the other of said first pair of nubs for downwardly folding said sheet adjacent the leading lip of said flange;

8. means adjacent and downstream of said side folding means and adjacent the sides of said belt for downwardly creasing corners of said sheet adjacent the trailing corners of said flange; and

9. means communicating with said means for downwardly creasing the corners of said sheet adjacent the trailing corners of said flange for downwardly folding said sheet adjacent the trailing lip of said flange.

23. An apparatus as in claim 22 wherein said means for downwardly creasing said sheet adjacent the trailing corners comprises:

a second pair of nubs, the nubs of said second pair of nubs being attached near the circumference of said discs in opposition to one another, the separation of said first pair of nubs from said second pair of nubs adjacent the circumference of said discs, being slightly greater than the dimension of said tray including said flange along the direction of movement of said belt.

24. An apparatus as in claim 23 including:

means for positioning said tray on said belt whereby said first pair of nubs contact said sheet on said tray adjacent the leading corners of said flange; and

means for rotating said discs in concert whereby the closest approaching point of said wheels to said belt travels in the same direction and at the same speed as said belt.

5: .A appa tus as insist! 24 here n a d fro t and rear tucking means comprise:

a pair of U-shaped members, one of which is in front of said tray and the other in the rear thereof, the arms of said U-shaped members extending below the level of said belt, and the bridges of said U- shaped members being extendable across the width of said belt. 

1. A process for applying a flexible cover to a continuously advancing open tray having a peripheral flange defining a leading lip, a trailing lip, side lips, leading corners and side corners, comprising: a. positioning a sheet of flexible material over the advancing tray so that the margins of the sheet project beyond the flange of the tray; b. folding downwardly at a folding station in one continuous motion the side margins, the leading margin and the trailing margin of the sheet adjacent the side lips, leading lip and trailing lip, respectively, of said flange; c. tucking the side margins of the sheet below the side lips of said flange; then d. tucking the leading margin of the sheet beneath the leading lip of said flange; and thereafter e. tucking the trailing margin of the sheet beneath the trailing lip of said flange so that the tucked margins conform to the contour of the flange.
 2. A process as in claim 1 including during and as a part of said folding step (b), creasing downwardly the corners of said sheet adjacent the leading corners of said flange.
 2. applicator means adjacent the path of movement of the tray for placing a flexible cover sheet on the tray;
 2. applicator means adjacent the path of movement of the tray for placing a flexible cover sheet on the tray;
 3. side folding means adjacent the sides of said belt for downwardly folding said sheet adjacent the side lips of said flange, comprising: a. a pair of rotatable wheels, said wheels being on opposite sides of said belt, said wheels being positioned so that their cylindrical surfaces hold the top of said sheet against the tops of the side lips of said flange at the point of contact of said cylindrical surfaces with said sheet; and b. a pair of rotatable discs, said discs being exterior of said wheels relative to said belt and concentric with said wheels whereby said discs and said wheels rotate as A unit, said discs having a larger diameter than said wheels.
 3. a folding station at which said sheet is positioned down around the periphery of said flange in a single continuous movement, comprising: a. a pair of rotatable wheels adjacent the Pg,23 sides of said belt and on opposite sides thereof, said wheels being positioned so that their cylindrical surfaces hold the top of said sheet against the tops of the side lips of said flange at the point of contact of said cylindrical surfaces with said sheet; b. a pair of rotatable discs exterior of said wheels relative to said belt and having a common axle with said wheels, said discs and said wheels being constrained to rotate as a unit, said discs having a larger diameter than said wheels, said discs serving to downwardly fold said sheet adjacent the side lips of said flange; c. leading lip folding means extending from one to the other of said discs and parallel to the common axle thereof near the circumferences thereof and d. trailing lip folding means extending from one to the other of said discs and parallel to the common axle thereof near the circumferences thereof, said trailing lip folding means being spaced from said leading lip trailing means adjacent the circumferences of said discs by a separation slightly greater than the dimension of said tray including said flange along the direction of movement of said belt;
 3. A process as in claim 2 including during and as a part of said folding step (b), creasing downwardly the corners of said sheet adjacent the trailing corners of said flange following said creasing downwardly of the margins of said sheet adjacent the leading corners of said flange.
 4. A process as in claim 3 including as an added step after said first tucking step (c), refolding downwardly at a refolding station in one continuous motion the side margins, the leading margin and the trailing margin of said sheet about the side lips, leading lip and trailing lip, respectively, of said flange.
 4. side tucking means adjacent the sides of said belt for tucking said sheet beneath the side lips of said flange; and
 4. side tucking means adjacent the sides of said belt for tucking said sheet beneath the side lips of said flange;
 5. front and rear tucking means adjacent and across the width of said belt for tucking said sheet beneath said flange adjacent the leading lip and the trailing lip, respectively, of said flange;
 5. front and rear tucking means downstream of said folding station adjacent and extending across the width of said belt for tucking said sheet beneath said flange adjacent the leading lip and the trailing lip, respectively, of said flange.
 5. An apparatus for applying a flexible cover to a tray having a peripheral flange, comprising:
 6. An apparatus as in claim 5 wherein said folding station includes leading corner creasing means communicating with said leading lip folding means and adjacent to said rotatable discs for downwardly creasing the corners of said sheet adjacent the leading corners of said flange.
 6. a first pair of nubs, the nubs of said first pair of nubs being attached near the circumferences of said discs in opposition to one another for downwardly creasing the corners of said sheet adjacent the leading corners of said flange.
 7. means extending from one to the other of said first pair of nubs for downwardly folding said sheet adjacent the leading lip of said flange;
 7. An apparatus as in claim 6 wherein said folding station includes trailing corner creasing means communicating with said trailing lip folding means and adjacent said rotatable discs for downwardly creasing the corners of said sheet adjacent the trailing corners of said flange.
 8. An apparatus as in claim 7 wherein said leading corner creasing means comprises a first pair of nubs attached near the circumferences of said discs in opposition to one another.
 8. means adjacent and downstream of said side folding means and adjacent the sides of said belt for downwardly creasing corners of said sheet adjacent the trailing corners of said flange; and
 9. means communicating with said means for downwardly creasing the corners of said sheet adjacent the trailing corners of said flange for downwardly folding said sheet adjacent the trailing lip of said flange.
 9. An apparatus as in claim 8 wherein said trailing corner creasing means comprises a second pair of nubs attached near the circumferences of said discs in opposition to one another.
 10. An apparatus as in claim 5, including downstream of said folding station:
 11. An apparatus as in claim 10, wherein said refolding station includes secondary leading corner creasing means communicating with said secondary leading lip folding means adjacent said second pair of discs for downwardly recreasing the corners of said sheet adjacent the leading corners of said flange.
 12. An apparatus as in claim 11, wherein said refolding station includes secondary trailing corner creasing means communicating with said secondary trailing lip folding means adjacent said second pair of discs for downwardly recreasing the corners of said sheet adjacent the traiing corners of said flange.
 13. A process as in claim 4, including during and as a part of said refolding step, recreasing downwardly the corners of said sheet adjacent the leading corners of said flange.
 14. A process as in claim 13 including during and as a part of said refolding step, recreasing downwardly the corners of said sheet about the trailing corners of said flange following said recreasing downwardly of the corners of said sheet adjacent the leading corners of said flange.
 15. An apparatus as in claim 5, wherein said front and rear tucking means comprise: a pair of U-shaped members, one of which is in front of said tray and the other in the rear thereof, the arms of said U-shaped members extending below the level of said belt, and the bridges of said U-shaped members being extendable across the width of said belt.
 16. An apparatus as in claim 5, wherein said side tucking means comprises a pair of shelves adjacent the sides of said belt.
 17. An apparatus as in claim 7, wherein said front and rear tucking means comprise: a pair of U-shaped members, one of which is in front of said tray and the other in the rear thereof, the arms of said U-shaped members extending below the level of said belt, and the bridges of said U-shaped members being extendable across the width of said belt.
 18. An apparatus as in claim 9, including: means for positioning said tray on said belt whereby said first pair of nubs contact said sheet on said tray adjacent the leading corners of said flange; and means for rotating said discs in concert whereby the closest approaching point of said wheels to said belt travels in the same direction and at the same speed as said belt.
 19. An apparatus as in claim 18, wherein said front and rear tucking means comprise: a pair of U-shaped members, one of which is in front of said tray and the other in the rear thereof, the arms of said U-shaped members extending below the level of said belt, and the bridges of said U-shaped members being extendable across the width of said belt.
 20. An apparatus as in claim 12, including downstream of said refolding station: means for smoothing said sheet atop said side lips of said flange.
 21. A process as in claim 14 including as an added step after said first tucking step (c) smoothing the margins of said sheet atop said side lips.
 22. An apparatus for applying a flexible cover to a tray having a peripheral flange which comprises:
 23. An apparatus as in claim 22 wherein said means for downwardly creasing said sheet adjacent the trailing corners comprises: a second pair of nubs, the nubs of said second pair of nubs being attached near the circumference of said discs in opposition to one another, the separation of said first pair of nubs from said second pair of nubs adjacent the circumference of said discs, being slightly greater than the dimension of said tray including said flange along the direction of movement of said belt.
 24. An apparatus as in claim 23 including: means for positioning said tray on said belt whereby said first pair of nubs contact said sheet on said tray adjacent the leading corners of said flange; and means for rotating said discs in concert whereby the closest approaching point of said wheels to said belt travels in the same direction and at the same speed as said belt.
 25. An apparatus as im claim 24 wherein said front and rear tucking means comprise: a pair of U-shaped members, one of which is in front of said tray and the other in the rear thereof, the arms of said U-shaped members extending below the level of said belt, and the bridges of said U-shaped members being extendable across the width of said belt. 